Twenty-eight endangered species and natural monuments have disappeared from the Nakdong River, one of South Korea’s four major rivers, in the wake of a massive government project to restore them, a lawmaker said Monday.

Costing 22.2 trillion won (US$19.5 billion), the project to restore the Han, Nakdong, Geum and Yeongsan rivers was a flagship project of the former Lee Myung-bak administration aimed at preventing floods and enhancing national water management.

Rep. Chang Ha-na of the main opposition Democratic Party, quoting an Environment Ministry report, said the river was a habitat for 49 legally protected species such as endangered species or natural monuments before the project began, but 28 of them were not found in a 2012 survey.

Among wildlife that no longer inhabit the river are 23 species of birds, three types of mammals and two types of amphibians and reptiles. The absent species included Chinese egret, blackfaced spoonbill, Steller’s sea eagle and oriental white stork, all designated first-grade endangered species and natural monuments, Chang said.

The ministry report described the environmental impact of the restoration project on the Nakdong River, which flows through the Gyeongsang provinces into the East China Sea.

The report compared the results of the 2012 survey conducted in the third year of the four-river project with studies and environmental surveys conducted before the project began.

The project has faced criticism for possible adverse effects on the environment. Many environmental experts and civic groups claim that dams built for the project have damaged the ecosystem.